It is indeed possible that the Microsoft PDF printer is “faster” at least with some applications because it directly translates XPS to PDF. If you have a more traditional Windows application that outputs GDI to the driver, there is an additional step in the Microsoft PDF printer that converts GDI to XPS before the driver converts XPS to PDF.
On the other hand, the Adobe PDF printer driver generates PostScript from GDI (or accepts “pass-through” PostScript from PostScript-centric applications) and sends that PostScript to the Acrobat Distiller for conversion of PostScript to PDF. That extra step make take a bit extra time, but considering the “issues” that the Microsoft PDF printer has, that extra time is very well worth it.
Some of the limitations of the Microsoft PDF printer:
- Problems handling embedding of anything other than TrueType fonts (forget about Type 1 or OpenType CFF fonts).
- All output is DeviceRGB. No capability to convert R=G=B to grayscale or support of CMYK passthrough.
- No option for image handling in terms of downsampling and compression types.
So, if speedy junk is your game, go with what Microsoft provides. 
- Dov